Page({
  data:{
    btn:"a",
    src:"./images/a.png",
    list:['a','b','c','d','e','f','g']    
},
change(e){
  let dataArr=e.currentTarget.dataset
  let name=dataArr.name
  this.setData({btn:name,src:"./images/"+name+".png"})
}
})
